La Amazonia es la selva tropical más grande del planeta, la cual abarca alrededor de 6.5 millones de kilómetros cuadrados, aunque se ha perdido mucho (alrededor de 18-20 por ciento) en las últimas décadas. El gran bosque muy probablemente también contiene la mayor biodiversidad de especies en la tierra; por ejemplo, una sola hectárea en el Parque Nacional Yasuní contiene más especies de árboles que todos los EE.UU. y Canadá juntos. Sin embargo, una nueva investigación publicada en las Actas de la Academia Nacional de Ciencias (PNAS) encuentra que hace muy poco, apenas unos 500 años, parte importante del sur de la Amazonía no era el bosque de altura con dosel que es hoy, sino que era sabana.
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Have you ever wondered if the cute light rail systems some large cities are installing actually get people out of their cars and have a positive environmental impact? For the first time, researchers have shown that installing light rail on an existing traffic corridor not only gets people out of their cars, but reduces congestion and air pollution. In the study, planners at the University of Utah measured impacts of a new light rail line in Salt Lake City (University Line) on an existing major thoroughfare (400/500 South). Their analysis showed that traffic near the University has fallen to levels not seen since the 1980s, even as the number of students, faculty and staff at the U has increased, and the commercial district along the corridor has expanded.
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Log books from British whaling ships more than 200 years ago have given new insights into the history of the Arctic sea ice, reports Tim Radford. A new study reveals that the scale of ice melt in the Arctic over the last few decades is new and unprecedented. The retreat of the ice in the last 30 years is part of a more recent and new pattern of climate change. British whaling ships from Tyneside in the north-east of England made 458 trips to the edge of the Arctic ice between 1750 and 1850.
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Super Moons are full moons that are extra, well, super! They are super because they appear larger in the evening sky than your run of the mill full moon. In June of last year, a full Moon made headlines. The news media called it a "supermoon" because it was 14% bigger and 30% brighter than other full Moons of 2013. Around the world, people went outside to marvel at its luminosity. If you thought one supermoon was bright, how about three? The full Moons of summer 2014—July 12th, August 10th, and Sept. 9th--will all be supermoons. The scientific term for the phenomenon is "perigee moon." Full Moons vary in size because of the oval shape of the Moon's orbit. The Moon follows an elliptical path around Earth with one side ("perigee") about 50,000 km closer than the other ("apogee"). Full Moons that occur on the perigee side of the Moon's orbit seem extra big and bright.
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Un nuevo estudio dirigido por la Universidad de Yale cuantifica por primera vez las principales causas de la "isla de calor urbana " (ICU), un fenómeno común que hace que las áreas urbanas del mundo sean considerablemente más calientes que los alrededores y puede incrementar los riesgos de salud para los residentes de la ciudad.
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In a study that may both reflect and foretell a warming planet's impact on human health, a research team found a link between hot days and kidney stones in 60,000 patients in several US cities with varying climates. "We found that as daily temperatures rise, there is a rapid increase in the probability of patients presenting over the next 20 days with kidney stones," said study leader Gregory E. Tasian, MD, MSc, MSCE, a pediatric urologist and epidemiologist at The Children's Hospital of Philadelphia (CHOP), who is on the staff of the Hospital's Kidney Stone Center as well as the Hospital's Center for Pediatric Clinical Effectiveness (CPCE).
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